/* global define */
(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    /*AMD. Register as an anonymous module.
     *define([], factory); */
    define([], factory());
  } else if (typeof module === 'object' && module.exports) {
    /*Node. Does not work with strict CommonJS, but
        // only CommonJS-like environments that support module.exports,
        // like Node.*/
    module.exports = factory();
  } else {
    /*Browser globals (root is window)*/
    root['watermark'] = factory();
  }
})(this, function () {
  /*Just return a value to define the module export.*/
  var watermark = {};

  var defaultSettings = {
    watermark_id: 'wm_div_id', //水印总体的id
    watermark_prefix: 'mask_div_id', //小水印的id前缀
    watermark_txt: '测试水印', //水印的内容
    watermark_time: '', //时间
    watermark_x: 20, //水印起始位置x轴坐标
    watermark_y: 20, //水印起始位置Y轴坐标
    watermark_rows: 0, //水印行数
    watermark_cols: 0, //水印列数
    watermark_x_space: 50, //水印x轴间隔
    watermark_y_space: 50, //水印y轴间隔
    watermark_font: '微软雅黑', //水印字体
    watermark_color: 'black', //水印字体颜色
    watermark_fontsize: '18px', //水印字体大小
    watermark_alpha: 0.15, //水印透明度，要求设置在大于等于0.005
    watermark_width: 100, //水印宽度
    watermark_height: 100, //水印长度
    watermark_angle: 15, //水印倾斜度数
    watermark_parent_width: 0, //水印的总体宽度（默认值：body的scrollWidth和clientWidth的较大值）
    watermark_parent_height: 0, //水印的总体高度（默认值：body的scrollHeight和clientHeight的较大值）
    watermark_parent_node: null //水印插件挂载的父元素element,不输入则默认挂在body上
  };

  /*加载水印*/
  var loadMark = function () {
    /*采用配置项替换默认值，作用类似jquery.extend*/
    if (arguments.length === 1 && typeof arguments[0] === 'object') {
      var src = arguments[0] || {};
      for (var key in src) {
        if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key]) continue;
        /*veronic: resolution of watermark_angle=0 not in force*/ else if (
          src[key] ||
          src[key] === 0
        )
          defaultSettings[key] = src[key];
      }
    }

    /*如果元素存在则移除*/
    var watermark_element = document.getElementById(defaultSettings.watermark_id);
    if (watermark_element) {
      var _parentElement = watermark_element.parentNode;
      if (_parentElement) {
        _parentElement.removeChild(watermark_element);
      }
    }

    /*获取页面最大宽度*/
    var page_width =
      Math.max(document.body.scrollWidth, document.body.clientWidth) -
      defaultSettings.watermark_width / 2;
    /*获取页面最大长度*/
    var page_height =
      Math.max(
        document.body.scrollHeight,
        document.body.clientHeight,
        document.documentElement.clientHeight
      ) -
      defaultSettings.watermark_height / 2;

    var setting = arguments[0] || {};
    var parentEle = defaultSettings.watermark_parent_node;

    var page_offsetTop = 0;
    var page_offsetLeft = 0;
    if (setting.watermark_parent_width || setting.watermark_parent_height) {
      setting.watermark_parent_width
        ? (page_width = setting.watermark_parent_width - defaultSettings.watermark_width / 2)
        : defaultSettings.watermark_parent_node
          ? (page_width = parentEle.offsetWidth - defaultSettings.watermark_width / 2)
          : void 0;
      setting.watermark_parent_height
        ? (page_height = setting.watermark_parent_height - defaultSettings.watermark_height / 2)
        : defaultSettings.watermark_parent_node
          ? (page_height =
            Math.max(parentEle.offsetHeight, parentEle.scrollHeight) -
            defaultSettings.watermark_height / 2)
          : void 0;

      /*指定父元素同时指定了宽或高*/
      if (parentEle) {
        page_offsetTop = parentEle.offsetTop || 0;
        page_offsetLeft = parentEle.offsetLeft || 0;
        defaultSettings.watermark_x = defaultSettings.watermark_x + page_offsetLeft;
        defaultSettings.watermark_y = defaultSettings.watermark_y + page_offsetTop;
      }
    } else {
      if (parentEle) {
        page_offsetTop = parentEle.offsetTop || 0;
        page_offsetLeft = parentEle.offsetLeft || 0;
        page_width = parentEle.offsetWidth - defaultSettings.watermark_width / 2 || 0;
        page_height =
          Math.max(parentEle.offsetHeight, parentEle.scrollHeight) -
          defaultSettings.watermark_height / 2 || 0;

        defaultSettings.watermark_x = defaultSettings.watermark_x + page_offsetLeft;
        defaultSettings.watermark_y = defaultSettings.watermark_y + page_offsetTop;
      }
    }

    /*创建水印外壳div*/
    var otdiv = document.getElementById(defaultSettings.watermark_id);
    var shadowRoot = null;

    if (!otdiv) {
      otdiv = document.createElement('div');

      /*创建shadow dom*/
      otdiv.id = defaultSettings.watermark_id;
      otdiv.style.pointerEvents = 'none';
      otdiv.style.position = 'fixed';
      otdiv.style.left = '0';
      otdiv.style.right = '0';
      otdiv.style.top = '0';
      otdiv.style.bottom = '0';
      otdiv.style.whiteSpace = 'pre';

      /*判断浏览器是否支持attachShadow方法*/
      if (typeof otdiv.attachShadow === 'function') {
        /* createShadowRoot Deprecated. Not for use in new websites. Use attachShadow*/
        shadowRoot = otdiv.attachShadow({ mode: 'open' });
      } else {
        shadowRoot = otdiv;
      }

      /*将shadow dom随机插入body内的任意位置*/
      var nodeList = document.body.children;
      var index = Math.floor(Math.random() * (nodeList.length - 1));
      if (nodeList[index]) {
        document.body.insertBefore(otdiv, nodeList[index]);
      } else {
        document.body.appendChild(otdiv);
      }
    } else if (otdiv.shadowRoot) {
      shadowRoot = otdiv.shadowRoot;
    }

    /*三种情况下会重新计算水印列数和x方向水印间隔：1、水印列数设置为0，2、水印长度大于页面长度，3、水印长度小于于页面长度*/
    var frontWidth =
      defaultSettings.watermark_x +
      page_offsetLeft +
      defaultSettings.watermark_width * defaultSettings.watermark_cols +
      defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1);
    if (
      defaultSettings.watermark_cols == 0 ||
      frontWidth + defaultSettings.watermark_width < page_width ||
      frontWidth > page_width
    ) {
      defaultSettings.watermark_cols = parseInt(
        (page_width - defaultSettings.watermark_x + page_offsetLeft) /
        (defaultSettings.watermark_width + defaultSettings.watermark_x_space / 2)
      );
      var temp_watermark_x_space = parseInt(
        (page_width -
          defaultSettings.watermark_x +
          page_offsetLeft -
          defaultSettings.watermark_width * defaultSettings.watermark_cols) /
        defaultSettings.watermark_cols
      );
      defaultSettings.watermark_x_space = temp_watermark_x_space
        ? defaultSettings.watermark_x_space
        : temp_watermark_x_space;
    }

    /*三种情况下会重新计算水印列数和x方向水印间隔：1、水印列数设置为0，2、水印长度大于页面长度，3、水印长度小于于页面长度*/
    var frontHeight =
      defaultSettings.watermark_y +
      page_offsetTop +
      defaultSettings.watermark_height * defaultSettings.watermark_rows +
      defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1);
    if (
      defaultSettings.watermark_rows == 0 ||
      frontHeight + defaultSettings.watermark_height < page_height ||
      frontHeight > page_height
    ) {
      defaultSettings.watermark_rows = parseInt(
        (page_height - defaultSettings.watermark_y + page_offsetTop) /
        (defaultSettings.watermark_height + defaultSettings.watermark_y_space / 2)
      );
      var temp_watermark_y_space = parseInt(
        (page_width -
          defaultSettings.watermark_x +
          page_offsetLeft -
          defaultSettings.watermark_width * defaultSettings.watermark_cols) /
        defaultSettings.watermark_cols
      );
      defaultSettings.watermark_y_space = temp_watermark_y_space
        ? defaultSettings.watermark_y_space
        : temp_watermark_y_space;
    }

    var x;
    var y;
    for (var i = 0; i < defaultSettings.watermark_rows; i++) {
      y =
        defaultSettings.watermark_y +
        (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;
      for (var j = 0; j < defaultSettings.watermark_cols - 1; j++) {
        x =
          defaultSettings.watermark_x +
          (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;

        var mask_div = document.createElement('div');
        //var oText = document.createTextNode(defaultSettings.watermark_txt);
        //var oTime = document.createTextNode(defaultSettings.watermark_time);
        // mask_div.appendChild(oText);
        mask_div.innerHTML = defaultSettings.watermark_txt + '\n' + defaultSettings.watermark_time;
        /*设置水印相关属性start*/
        mask_div.id = defaultSettings.watermark_prefix + i + j;
        /*设置水印div倾斜显示*/
        mask_div.style.webkitTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
        mask_div.style.MozTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
        mask_div.style.msTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
        mask_div.style.OTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
        mask_div.style.transform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
        mask_div.style.visibility = '';
        mask_div.style.position = 'absolute';
        /*选不中*/
        mask_div.style.left = x + 'px';
        mask_div.style.top = y + 'px';
        mask_div.style.overflow = 'hidden';
        mask_div.style.zIndex = '9999999';
        mask_div.style.opacity = defaultSettings.watermark_alpha;
        mask_div.style.fontSize = defaultSettings.watermark_fontsize;
        mask_div.style.fontFamily = defaultSettings.watermark_font;
        mask_div.style.color = defaultSettings.watermark_color;
        mask_div.style.textAlign = 'center';
        mask_div.style.width = defaultSettings.watermark_width + 'px';
        mask_div.style.height = defaultSettings.watermark_height + 'px';
        mask_div.style.display = 'block';
        mask_div.style['-ms-user-select'] = 'none';
        /*设置水印相关属性end*/
        shadowRoot.appendChild(mask_div);
      }
    }
  };

  /*移除水印*/
  var removeMark = function () {
    /*采用配置项替换默认值，作用类似jquery.extend*/
    if (arguments.length === 1 && typeof arguments[0] === 'object') {
      var src = arguments[0] || {};
      for (var key in src) {
        if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key]) continue;
        /*veronic: resolution of watermark_angle=0 not in force*/ else if (
          src[key] ||
          src[key] === 0
        )
          defaultSettings[key] = src[key];
      }
    }

    /*移除水印*/
    var watermark_element = document.getElementById(defaultSettings.watermark_id);
    var _parentElement = watermark_element.parentNode;
    _parentElement.removeChild(watermark_element);
  };

  /*初始化水印，添加load和resize事件*/
  watermark.init = function (settings) {
    loadMark(settings);
    window.addEventListener('load', function () {
      loadMark(settings);
    });
    window.addEventListener('resize', function () {
      loadMark(settings);
    });
    window.addEventListener('DOMContentLoaded', function () {
      loadMark(settings);
    });
  };

  /*手动加载水印*/
  watermark.load = function (settings) {
    loadMark(settings);
  };

  /*手动移除水印*/
  watermark.remove = function () {
    removeMark();
  };

  return watermark;
});